The present invention relates to a motion regulator for a hinge and, more particularly, to a motion regulator for a tripartite eyeglass hinge which includes at least two hinge tabs and a hinge screw, a rigid sleeve surrounding the hinge screw disposed in a hinge eye of a hinge tab, with the sleeve projecting beyond the hinge tab and resting against a neighboring hinge tab or tabs in such a manner that the sleeve rotates with the tab or tabs, and wherein at least one element is provided which is in contact, under a pretensioning, with a contact surface, rotationally symmetrical with respect to the hinge axis of at least one hinge tab.
In, for example, German Patent No. 1,117,911, hinges having interlocking hinge tabs for eyeglass frames are proposed wherein a hinge screw, surrounding by a sleeve, is located in the bores of the hinge tabs. In this proposed construction, the sleeve is fashioned of a plastic material, with a length of the sleeve being larger, by a predetermined amount, than a total length of the associated bores of the hinge tabs. When the eyeglass hinge is screwed or threadably secured together, the sleeve is compressed between the underside of the screw head and an end face of the hinge tab, whereby a certain degree of friction is produced. Since the sleeve contacts the head of the hinge screw, the hinge joint may loosen during pivotal movements of the parts attached to the hinge. Since the braking torque between the hinge halves depends essentially on the tightening torque of the hinge screw, blockage of the hinge may occur in case of the application of too high a tightening torque. After certain period of usage, and with a low tightening torque, the braking torque may no longer be adequate to prevent dropping of the temple, attached to the hinge due to gravity.
In, for example, DOS 2,039,455 an eyeglass hinge is proposed where a sleeve, slides in the axial direction and exhibits a predetermined pretensioning, is inserted in a hinge tab. The end faces of the sleeve, projecting beyond the hinge tab, are in pressure contact with the end faces of neighboring hinge tabs. The friction torque of the hinge is independent of the tightening torque of the screw in this arrangement and is determined by the sleeve in contact in the radial direction. Also in this proposed hinge, drooping of the temple can occur after a certain usage. That is, relaxing of the braking torque can take place since the movement of the sleeve in the radial direction is no longer possible once the hinge screw has been tightened, adjustment of the hinge screw results in an axial vise grip on the sleeve.
In, for example, U.S. Pat. No. 1,867,346 a motion regulating hinge is proposed which includes an element resilient in the axial direction, with the hinge being intended for windows, doors, or the like. A disadvantage to this proposed arrangement resides in the fact that while the friction torque of the hinge screw is independent of the tightening torque of the screw, the tightening torque of the screw must be supported by the external hinge tabs which latter, for that purpose, must be correspondingly firm or rigid.
In, for example, DOS 2,828,980, a hinge is proposed wherein synthetic resin shims with collar sleeves are inserted between the hinge eyes. The collar sleeves may be in contact with each other or they may be formed integrally with the synthetic resin shim. By axial tightening of the screw, the motion regulation is effected. However, a disadvantage of this arrangement resides in the fact that the contact point of the brake surfaces is dependent on the tightening torque of the hinge screw. Moreover, there is a possibility of a relative movement between the collar sleeves and the outer hinge tab. The aim underlying the present invention essentially resides in providing a hinge of the aforementioned type wherein a friction torque of the hinge is independent of the tightening torque of the screw, with the braking torque, determining the motion characteristic of the hinge, being substantially constant over a long period of time. In accordance with advantageous features of the present invention, the element is spring-elastic, and is located at least between a hinge tab wherein a sleeve is arranged and neighboring hinge tab or tabs movable relative to this hinge tab, and is in contact with the contact surface with resilience in the axial direction with respect to the hinge screw axis.
In accordance with advantageous features of the present invention, a rigid sleeve is disposed in a hinge tab, with the sleeve, after tightening of the hinge screw, being immovable with respect to the neighboring hinge tab or tabs and, respectively, with respect to the hinge screw. By virtue of the rigid sleeve, a constant spacing between the elements contacted by the sleeve is determined, with the spacing being independent of the tightening torque of the hinge screw. A spring-elastic element is located between the hinge tab, wherein the sleeve is arranged and the neighboring hinge tab movable relatively to this hinge tab. The spring-elastic element extends essentially in a radial direction and is located on a side of the rigid sleeve facing away from the hinge screw. The spring-elastic element is disposed in a space extending in an axial direction between the contact surface or surfaces and, for example, the level of the rigid sleeve end in contact with the neighboring hinge tab. The height of the space is dimensioned so that the spring-elastic element is movable in an axial direction, and no effect is exerted on the spring-elastic element either by the hinge screw or by the neighboring hinge tabs. The braking moment exerted by the spring-elastic element on the hinge tab or tabs is dependent solely on the pretensioning with which the element rests against the contact surface or surfaces. As soon as the hinge screw has been tightened, a constant braking torque results independently of whether the hinge screw was mounted with a weak or a strong tightening torque.
In contradistinction to the state of the art proposals, in accordance with the present invention, the surface, by way of which the sleeve rests against the neighboring hinge tab, can be dimensioned so that no plastic deformation occurs due to excessive contact pressure. A blockage of the hinge due to the application of a heightening torque is excluded or prevented so that the braking torque and therefore, the motion characteristic of the hinge remains substantially constant over a long period of time.
Preferably, in accordance with the present invention, the spring-elastic element is nonrotatibly or nonrotationally fixed with respect to a hinge tab and rests under a pretensioning against the contact surface of the other hinge tab.
In accordance with still further features of the present invention, the spring-elastic element is a plate spring or, alternatively, may be formed as a corrugated spring ring.
The contact surface on which the spring-elastic element rests does not extend in parallel to the hinge screw axis but rather at an angle thereto. Preferably, according to the invention, the contact surface is oriented or disposed approximately perpendicularly to the hinge screw axis. In any event, the spring-elastic element acts on the contact surface substantially in the axial direction.
In accordance with still further features of the present invention, the spring elastic element is connected with the sleeve and, more particularly, the spring-elastic element is arranged nonrotatably or nonrotationally on the sleeve and, preferably is rigidly joined to the sleeve. Thereby, the spring-elastic element will, in all cases contact the contact surface in the same area of the latter.
Advantageously, according to the present invention, the sleeve may include two spring-elastic elements. In this arrangement, pressure and thus a braking torque are exerted on the hinge tab by way of respectively one contact surface in the zone of each end face of the hinge tab wherein the sleeve is inserted.
Moreover, according to the present invention, the spring-elastic element may be integrally formed with the sleeve and, the two spring-elastic elements, in a zone of each end face of the hinge tab when the sleeve is inserted may be provided with a contact surface with the respective spring-elastic elements being in contact with the respective contact surfaces.
According to the present invention, the sleeve, acting as a spacer member, is not made of one piece but rather includes a basic sleeve member and a ring at which the latter spring-elastic element is integrally formed therewith or is connected thereto.
In accordance with still further advantageous features of the present invention, the sleeve may be formed integrally with the hinge screw and constitute a cylindrical extension. The spring-elastic element, described hereinabove, rests on at least one contact surface and brakes the associated hinge tab. An indentation may be provided for this purpose in the hinge tab wherein the sleeve is inserted. In this situation, the bottom surface of the indentation serves as a contact surface. However, the indentation may also be provided partially in the hinge tab wherein the sleeve is inserted and partially in the neighboring hinge tab or completely in such hinge tab. In the last mentioned situation, an end face of the hinge tab with the sleeve inserted therein serves as the contact surface.
Moreover, it is possible for the spring-elastic element of the present invention be surrounded by a supporting ring, the outer diameter of which is approximately equal to an outer diameter of the central hinge tab, wherein the height of the central hinge tab is smaller by more than a height of the supporting ring than the length of the sleeve.
The supporting ring may be rigidly joined to the sleeve and respectively to the ring with the sleeve including two sleeve sections which contact each other in an assembled condition.
It is also possible in accordance with the present invention to provide a motion regulator wherein a 0-ring is arranged in a zone wherein the spring-elastic element is disposed at the sleeve, with the 0-ring being in contact with the sleeve, and with the spring-elastic element and with the hinge tab which latter is also in contact with the spring-elastic element under a pretensioning. By virtue of this arrangement, advantageously, a spring progression is exhibited that rises gradually and thus is tolerance-insensitive.
The above objects, features, and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings which show, for the purpose of illustration only, several embodiments in accordance with the present invention.